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Archive 2022 · Bryan/TDP tested the RF800/5.6

bman212121
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p.2 #1 · p.2 #1 · Bryan/TDP tested the RF800/5.6

Uarctos wrote:
2X is 100% more, 3X is 200% more. 800mm is 100% more than 400mm, and 1200mm is 200% more than the same 400mm.
Nobody is saying that the latest RF lenses are bad. They are way too expensive and less versatile.

No, that is inaccurate. An 800mm lens is 4x more than a 400mm lens, so in percentage terms if 400mm = 100% than 300% more than 100% is 800, aka 400% total.

When you say 800mm, it's a circle, not a single dimension.

"PI"r2 (Pi x radius squared)

400mm = 3.14 x 200mm x 200mm = 125,600
800mm = 3.14 x 400mm x 400mm = 502,400

800mm 4 = 400mm
502,400 4 = 125,600

This is the math of what I hadn't every really done myself previously to realize how much of a difference lens changes are. Any time you double the length of a lens it would be the same as quadrupling the MP in the camera. So lens length has a much bigger impact on final resolution does than changes in sensor resolution. For pixels / mm you can increase it much faster with a bigger lens than you can with camera bodies.

Jun 22, 2022 at 11:51 AM

Imagemaster
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p.2 #2 · p.2 #2 · Bryan/TDP tested the RF800/5.6

tkbslc wrote:
Before you act too condescending, you may want to make sure you know what is being discussed or you might embarrass yourself.

We are talking about the RF 800mm f5.6, which is $17000, weighs 6.9lbs and does in fact have an aperture of f5.6. Nobody is talking about the cheapo 800mm f11.

Yes, sorry, my boo-boo.

It is still not a 400mm f2.8 with a welded 2xTC.

Jun 22, 2022 at 12:26 PM

Uarctos
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p.2 #3 · p.2 #3 · Bryan/TDP tested the RF800/5.6

I'm talking mm, not mm² (aka area).
Anyway, because 800mm is double the lenghth of the 400mm, then for the two axis of your image ( the image is bidimensional, mot a circle) you'll have 4 times more pixels on the duck, aka 300% more pixels on the duck.

Jun 22, 2022 at 12:28 PM

AmbientMike
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p.2 #4 · p.2 #4 · Bryan/TDP tested the RF800/5.6

Doubling the fl on a duck that you have to crop anyway gives 4x the pixels (4x the area,) and 2x the resolution. Resolution is linear. Pixels are area.

Jun 22, 2022 at 12:59 PM

AmbientMike
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p.2 #5 · p.2 #5 · Bryan/TDP tested the RF800/5.6

Z250SA wrote:
IIRC, with no guarantee, one of the few issues with Bryans test results is that the tests are shot at minimum focus distance or at least close to. Few lenses are at their strongest at MFD, the long teles perhaps least of all.

He has been the one who _finally_ convinced me to get several lenses. I should, or actually Canon should, pay him a few monetary effects for his thorough work.

But my experiences have not correlated with his in a few cases, especially regarding his test charts. I have found the lenses to be better that his charts appear...Show more →

Someone posted a TDP link clearly demonstrating the 150-600 Tamron at 600 beat the 180 IIRC. So I'm hesitant to buy into too much. My 75-300 III not nearly as bad as his review, perhaps older versions not as good? Not sure of the explanation.

Jun 22, 2022 at 01:01 PM

Toothwalker
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p.2 #6 · p.2 #6 · Bryan/TDP tested the RF800/5.6

bman212121 wrote:
He as in you asked him or just looking at the site? Just curious because it does seem like he knows quite a few people and he talks to other people I would generally trust their opinion's on. I look at his site simply because others paint him in a positive light and it's quite hard to get actual trustworthy information around such niche products.

It does seem like sometimes the charts tend to be a more worst case scenario, but what I'd really be interested in is if you ever had an experience where his charts were better than what...Show more →

It is well known that lens performance is a function of the aperture. Lens tests are therefore normally presented for several f-numbers. It is also well known that lens performance is a function of the position in the field. Borders and corners are weaker than the image center. Lens test therefore examine the image center, borders, and corners separately. It is less well known that lens performance is a function of the object distance, especially for lenses with a large maximum aperture and/or an asymmetrical design. The impact of the object distance can be as big as, or even larger than, the impact of the aperture.

Bryan is a dedicated tester who pays great attention to detail. He has a careful test methodology, but he cannot avoid the laws of physics. His standard ISO test chart is about 1.4 m wide, and further he writes "focal lengths over 460mm may be tested on a smaller-sized target".

Add to this that most photographic lenses are optimized for infinity focus, or at least a considerable distance, the findings of Z250SA make sense. It all depends on the lens design. If it incorporates floating elements for close focus correction, the impact of object distance may be moderate. If it does not, a lens may fall apart at MFD.

If TDP's charts are better than what we experience, it usually means that we bought a lemon.

Jun 22, 2022 at 03:55 PM

bman212121
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p.2 #7 · p.2 #7 · Bryan/TDP tested the RF800/5.6

Uarctos wrote:
I'm talking mm, not mm² (aka area).
Anyway, because 800mm is double the lenghth of the 400mm, then for the two axis of your image ( the image is bidimensional, mot a circle) you'll have 4 times more pixels on the duck, aka 300% more pixels on the duck.

Yes that's what I'm getting at. It's twice the resolution in PPI measure for a single axis, but since we're not taking photos in one dimension it's important to note that the total area is not increasing in a linear fashion. The nitpick is simply because a 400mm f5.6 -> 800mm f5.6 isn't twice as big of a lens, it's actually 4x as big of a lens. It helps put into perspective why these cost so much and why doubling a lens focal length has a better impact to image quality than doubling the MP on a camera.

Jun 22, 2022 at 04:00 PM

arbitrage
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p.2 #8 · p.2 #8 · Bryan/TDP tested the RF800/5.6

Imagemaster wrote:
Yes, sorry, my boo-boo.

It is still not a 400mm f2.8 with a welded 2xTC.

If you look at the lens diagrams and then look at an EF 2xTCIII diagram you can see it is pretty darn close

Jun 22, 2022 at 06:01 PM

Z250SA
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p.2 #9 · p.2 #9 · Bryan/TDP tested the RF800/5.6

bman212121, nice to see someone trying to bring some correct maths to the table! I guess you are rather young? Pleace enjoy. Lifetime is exponential, I´m slowly accepting...

I dived into all the optical stuff including the maths some 15 years ago as I found it valuable to understand the science and not just forum dynamics when selecting the next lens. I found photography to be more fun than testing the optics, so I moved on to here.

But imagine how Bryan makes his tests. He shoots, is it Siemens(?), test charts or what ever they are called, that specific model. Imagine him testing at longer distances. Imagine him focusing on test charts the size of large buildings to get even half way to something pretending to be infinity. There is no need to ask anyone how it is done. When shooting test charts, they will be rather small. Anything else is more or less totally impractical.

Yes, you can place one chart in the center and one in each corner. And with a 800mm you shoot from several 100m through more or less violent atmosphere. Do you then test the lens or the air? How do you know? Shoot a laser point into the chart to get a measure, a picture of the atmospherics? I did that at my most energetic point. Results? Just had to stop the madness...!

Jun 22, 2022 at 06:03 PM

bman212121
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p.2 #10 · p.2 #10 · Bryan/TDP tested the RF800/5.6

Not that young... But as always age is going to be relative to who is asking the question.

I get the gist of what he's doing, but like you said there are many variables involved. Without really knowing the person you're going on the assumption they know what they are doing. I posed the specific question because I like to confirm from multiple sources they have confidence that his work is the real deal. For every one person who can talk the talk, there are 10 others who can repeat enough technical jargon to make them seem like they understand what's going on. *queue your favorite vlogger here*. Everything I've seen indicates Bryan is the real deal, but it's interesting to know who has worked with him in real life.

Being a techie person I do enjoy the intricacies around what makes a good image, and often look for reading material that digs into the why. My primary goal really revolves around finding the next toy to play with for a BIF rental, for the one or two times we can get away a year. I've slowly progressed through all of the smaller combinations and have continued to push toward the larger end, but at certain point you have to step back and ask can I accomplish this same goal a different way? The most intriguing part for me is does this 800 f5.6 really offer something you simply cannot achieve through another means?

When I'm using the camera, it's definitely not test charts. My standard go to is an orange life preserver which has very small text on it. My unscientific tests reveal which combinations are able to provide the best real world resolution from a common distance I shoot at. I have a shooting position that I can easily recall even if it's on completely different days to shoot at a similar distance, but that is the a large portion of what I test the camera with. When I have the camera in hand it's generally for capturing photos, rather than testing lenses.

I really appreciate you taking the time to detail testing methodology. If I'm not shooting I'm always looking for ways to improve things that I can control outside of the time while shooting, and looking for new ways to utilize features on the camera to improve my photos. There is always something new to understand about how optics work, and how they interact with the camera to produce the final image. Understanding the optical path and how it's affecting the light gives you a better handle on light in general, and what you can do to make the most of it.

Jun 22, 2022 at 07:54 PM

Z250SA
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p.2 #11 · p.2 #11 · Bryan/TDP tested the RF800/5.6

212121, I suppose you have read the Zeiss papers about MTF´s and other optical aspects over at https://lenspire.zeiss.com/photo/en/article/overview-of-zeiss-camera-lenses-technical-articles

Of the testers I usually follow Lloyd Chambers and Roger Cicala are the closest to some form of Truth. They tend to test a small or larger sample of the lens in question. And if they are not satisfied, they start to dig into any issue they find. That I like! Bryan´s pages are so nice to read as well as informative and have that comparison of two side by side which I find very handy.

Jun 23, 2022 at 04:36 AM

TeamSpeed
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p.2 #12 · p.2 #12 · Bryan/TDP tested the RF800/5.6

AmbientMike wrote:
Someone posted a TDP link clearly demonstrating the 150-600 Tamron at 600 beat the 180 IIRC. So I'm hesitant to buy into too much. My 75-300 III not nearly as bad as his review, perhaps older versions not as good? Not sure of the explanation.

I would like to see a 100% crop sample from your lens to see how it appears on something with some detail like a flower or something. There are different versions of this lens, so I am curious which you have.

https://en.wikipedia.org/wiki/Canon_EF_75%E2%80%93300mm_lens

This review of the lens is one I could get behind, and the 100% cropped results posted in this article is what I remember from my different copies over the years. It is a good "memories" lens, but not one if you want detailed photos of subjects, like feathers in birds, etc.

https://www.bowerpowerblog.com/75-300m-canon-lens-review/

Edited on Jun 23, 2022 at 07:08 AM · View previous versions

Jun 23, 2022 at 05:56 AM

bman212121
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p.2 #13 · p.2 #13 · Bryan/TDP tested the RF800/5.6

Z250SA wrote:
212121, I suppose you have read the Zeiss papers about MTF´s and other optical aspects over at https://lenspire.zeiss.com/photo/en/article/overview-of-zeiss-camera-lenses-technical-articles

Of the testers I usually follow Lloyd Chambers and Roger Cicala are the closest to some form of Truth. They tend to test a small or larger sample of the lens in question. And if they are not satisfied, they start to dig into any issue they find. That I like! Bryan´s pages are so nice to read as well as informative and have that comparison of two side by side which I find very handy.

I've read quite a bit of Roger's stuff, which is what pointed me towards Bryan's site. Definitely have dug though a decent amount of his work as well. I've not come across Lloyd before, but I'll definitely check him out. The Zeiss paper does seem familiar, but it's been a while since the last time I have seen it.

Jun 23, 2022 at 06:42 AM

Z250SA
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p.2 #14 · p.2 #14 · Bryan/TDP tested the RF800/5.6

This site is also overwhelming of knowledge: http://www.marcocavina.com/articoli_tecnici_fotografici.htm if you truly want to learn.

And in the Language Beautiful! Google translate does help some.

Jun 23, 2022 at 03:44 PM

rscheffler
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p.2 #15 · p.2 #15 · Bryan/TDP tested the RF800/5.6

bman212121 wrote:
I haven't seen images from the lens yet but I've been curiously watching to see if it's as bad as everyone has made it out to be.

It's not lens test charts or brick walls, but you can see what Rob is doing with the 800/5.6 in the R3 image thread. Looks pretty good to me. IIRC he did one comparison against the RF 600/4 w/1.4x TC and the 800 was slightly better (higher contrast). But it's splitting hairs and for many, a 400 or 600 with TCs is probably going to be a more versatile and affordable solution.

Jun 23, 2022 at 04:58 PM

gimp_dad
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p.2 #16 · p.2 #16 · Bryan/TDP tested the RF800/5.6

RobAmy wrote:
Not much love for the lens from the above post, I am actually enjoying the lens myself

. The extenders work really well on the 800mm also.

Hey RobAmy, do you have an opinion on AF performance of RF400/2.8LIS + 2x vs RF800/5.6LIS? Looks like IQ might be pretty similar and 800mm is about my sweet spot for handheld FL anyway, so I could go RF400/2.8 and use the 2x I already have or buy the RF800/5.6. Only thing I'm questioning is which config will have faster AF with the R3.

I currently use the EF600/4LIII + 1.4xIII + adapter for my 800-ish mm needs but would enjoy the smaller lens if it performs well. Then I would sell the 600 since I don't use it very often without TC anyway.

Thanks for any insight you have to share.

Jun 23, 2022 at 05:02 PM

RobAmy
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p.2 #17 · p.2 #17 · Bryan/TDP tested the RF800/5.6

gimp_dad wrote:
Hey RobAmy, do you have an opinion on AF performance of RF400/2.8LIS + 2x vs RF800/5.6LIS? Looks like IQ might be pretty similar and 800mm is about my sweet spot for handheld FL anyway, so I could go RF400/2.8 and use the 2x I already have or buy the RF800/5.6. Only thing I'm questioning is which config will have faster AF with the R3.

I currently use the EF600/4LIII + 1.4xIII + adapter for my 800-ish mm needs but would enjoy the smaller lens if it performs well. Then I would sell the 600 since I don't use it very...Show more →

I have not tried the 2x comparison yet, been busy. I have used the 400mm + 2x a lot and I would say if you do not need the 1120mm or 1600mm the 400mm would be better. That is my all time favorite lens. That f2.8 is special when you can use it. I like the RF adapters better also. I doubt I will find the AF much better actually because the 2x performs outstanding on the 400mm. I bought the 800mm because it made more sense for me to pair with my 400mm vs the 600mm I sold. The 400mm with the 1.4x is outstanding at 560mm f4. I love Canon's 400mm and seeing the 800mm is a 400mm with a welded TC

it made perfect sense. I enjoy the better MFD, smaller size and it takes TC's well. I have less overlap between the 400mm and 800mm vs the 400mm and 600mm. If I choose to only keep one, it would be the 400mm hands down simply because of the f2.8 and the performance with TC's.

Jun 24, 2022 at 04:56 AM

Optics Patent
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p.2 #18 · p.2 #18 · Bryan/TDP tested the RF800/5.6

One basic point when going 2x is not to forget that not only do you magnify image shake and subject motion by 2x but you are darker (going from 2.8 to 5.6) and this require the shutter to be open twice as long, further amplifying motion effects. TANSTAAFL

Jun 24, 2022 at 06:34 AM

Imagemaster
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p.2 #19 · p.2 #19 · Bryan/TDP tested the RF800/5.6

Optics Patent wrote:
One basic point when going 2x is not to forget that not only do you magnify image shake and subject motion by 2x but you are darker (going from 2.8 to 5.6) and this require the shutter to be open twice as long, further amplifying motion effects. TANSTAAFL

I think most of us know that.

Jun 24, 2022 at 09:35 AM

gimp_dad
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p.2 #20 · p.2 #20 · Bryan/TDP tested the RF800/5.6

RobAmy wrote:
I have not tried the 2x comparison yet, been busy. I have used the 400mm + 2x a lot and I would say if you do not need the 1120mm or 1600mm the 400mm would be better. That is my all time favorite lens. That f2.8 is special when you can use it. I like the RF adapters better also. I doubt I will find the AF much better actually because the 2x performs outstanding on the 400mm. I bought the 800mm because it made more sense for me to pair with my 400mm vs the 600mm I sold. The...Show more →

Thanks for sharing your experience! I don't think there are too many people out there who actually have both the RF400/2.8 and the RF800/5.6 so it's helpful to hear your perspective. I was totally leaning toward the RF800/5.6 because I expected IQ and AF speed to be better and I really don't use a 400mm prime much at all (I still have my original EF400/2.8LIS purchased 19 years ago which got used 90+% of the time with the 2x TC attached). Now I'm not really sure but am tentatively leaning toward the 400. Either way, my principle goal is a very high quality hand-holdable 800 setup.

Jun 24, 2022 at 12:01 PM

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